Commit f7ba614 improved the internal consistency of the different
means of accessing routes, but it introduced some problems at the level
of code comments and user-visible strings.
This commit applies fixes on three levels:
Firstly, we remove or replace grammatically invalid constructs such as
"a routes" or "a particular routes".
Secondly, we make sure that we always use "the router DSL" or "the
router syntax", because this has always been the official terminology.
Finally, we make sure that we only use "routes" when referring to the
application-specific set of routes that are defined in the
"config/routes.rb" file, we use "router" when referring on a more
abstract level to "the code in Rails used to handle routing", and we use
"routing" when we need an adjective to apply to nouns such as
"url_helpers. Again this is consistent with historical practice and
other places in the documentation.
Note that this is not a sweep over the entire codebase to ensure
consistent usage of language; it is just a revision of the changes
introduced in commit f7ba614.
Signed-off-by: Wincent Colaiuta <win@wincent.com>
Signed-off-by: José Valim <jose.valim@gmail.com>

The documentation makes it sound like mail() only accepts a limited
set of headers in the headers hash, but it in fact accepts any
arbitrary headers, and there is a test ("can pass random headers in
as a hash to mail") for it in the test suite.
Signed-off-by: Wincent Colaiuta <win@wincent.com>

…e:resolved]
More work still needs to be done on some of these names
(render_template.action_view and render_template!.action_view particularly)
but this allows (for example) /^sql/ to subscribe to all
the various ORMs without further modification
Signed-off-by: José Valim <jose.valim@gmail.com>